Show simple item record

dc.contributor.advisorAl-Jumaily, Ahmed
dc.contributor.authorPuli, Venkata Sreenivas
dc.date.accessioned2008-04-18T01:17:23Z
dc.date.available2008-04-18T01:17:23Z
dc.date.copyright2006-01-01
dc.date.issued2006-01-01
dc.identifier.urihttp://hdl.handle.net/10292/264
dc.description.abstractThe positive temperature coefficient of resistivity (PTCR) sensors is resistor materials that undergo a sharp change in resistivity at a designed Curie temperature due to its unique structure and chemical composition. This effect serves important control functions in a wide variety of electronic circuitry and similar applications. Conventional calcining of mixed oxides method (CMO) is used for fabricating lanthanum doped barium titanate (BaTiO3) for PTCR behaviour through solid-state-sintering route, at 1100°C, 1350°C. Two batches of samples were fabricated at low and high sintering temperatures of 1100°C, 1350°C respectively. The effect of different concentrations of donor dopant on BaTiO3 on the electrical properties of Ba(1-x)LaxTiO3 with x= 0.0005, 0.001, 0.002, 0.0025, 0.003 mol%, is investigated at low sintering temperature. The influence of lantanum doping with Al2O3+SiO2+TiO2 (AST) as sintering aids on the electrical properties of Ba(1-x)LaxTiO3 with x= 0.0005, 0.001, 0.003 mol%, is also investigated. The results of the electrical characterization for the first batch of samples showed an increase in room temperature resistance with increaisng donor concentration. Also the results of the electrical characterization for the second batch of samples also showed the same increase in room temperature resistance with increasing donor concentration. For first batch of sensors the high room temperature resistance keeps the jump small and these materials showed V-shaped NTCR-PTCR multifunctional cryogenic sensor behavior with a strong negative coefficient of resistance effect at room temperature.Where as the second batch of sensors showed few orders of magnitude rise in resistivity values. The La-doped BaTiO3 ceramics co-doped with Mn gives an enhanced PTCR effect which can be exploited for various sensor applications.
dc.publisherAuckland University of Technology
dc.subjectCeramic materials - Thermal conductivity
dc.subjectCeramic materials - Electric properties
dc.subjectCeramic materials - Thermal properties
dc.subjectElectric conductivity
dc.subjectElectric resistance
dc.subjectEngineering
dc.titlePTCR effect in La2CO3 doped BaTiO2 ceramic sensors
dc.typeThesis
thesis.degree.grantorAuckland University of Technology
thesis.degree.levelMasters Theses
thesis.degree.nameMaster of Engineering
thesis.degree.disciplineSchool of Engineeringen_US
dc.rights.accessrightsOpenAccess


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record